In electrohydraulic servovalves having mechanical feedback elements included as a part thereof, it is not uncommon that the spring rate of the feedback member varies from one such valve to another. Such variation results from differences in manufacturing tolerances, materials and the like which are non-adjustable subsequent to the construction of the valve during production assembly.
If the particular spring rate of the feedback member is improper for the desired function of the particular valve, it is then necessary to replace the feedback element with one having a more appropriate spring rate. In the past, such replacement requires major disassembly of the entire servovalve and a consequent build up thereof after replacement of the feedback element with a different one having a proper spring rate. Such a necessity is time consuming, cumbersome and adds to the cost of the electrohydraulic servovalve.
The best prior art known to applicants are U.S. Pat. Nos.: 2,226,345; 2,704,997; 2,461,851; 3,554,084; 2,564,355.